25-08-2017, 09:32 PM
Motion Study and Work Design
Motion Study.ppt (Size: 1.67 MB / Downloads: 105)
Definitions
Motion study involves the analysis of the basic hand, arm, and body movements of workers as they perform work.
Work design involves the methods and motions used to perform a task.
This design includes
the workplace layout and environment
the tooling and equipment (e.g., work holders, fixtures, hand tools, portable power tools, and machine tools).
work design is the design of the work system.
Basic Motion Elements
Any manual task is composed of work elements, and the work elements can be further subdivided into basic motion elements. We will define basic motion elements and how they can be used to analyze work
Frank Gilbreth was the first to catalog (list) the basic motion elements.
Therbligs are the basic building blocks of virtually all manual work performed at a single workplace and consisting primarily of hand motions. – A list of Gilbreth’s 17 therbligs is presented along with the letter symbol used for each as well as a brief description.
With some modification, these basic motion elements are used today in a number of work measurement systems, such as Methods - Time Measurement (MTM) and the Maynard Operation Sequence Technique (MOST).
Methods analysis at the therblig level seeks to eliminate or reduce ineffective therbligs.
Some of the motion element names and definitions have been revised
Micromotion Analysis
Each therblig represents time and energy spent by a worker to perform a task. If the task is repetitive, of relatively short duration, and will be performed many times, it may be appropriate to analyze the therbligs that make up the work cycle as part of the work design process.
The term micromotion analysis is sometimes used for this type of analysis.
Objectives:
Eliminate ineffective therbligs if possible
Avoid holding objects with hand – Use workholder
Combine therbligs – Perform right-hand and left-hand motions simultaneously
Simplify overall method
Reduce time for a motion, e.g., shorten distance